/*
 * @Author: your name
 * @Date: 2020-12-19 15:39:04
 * @LastEditTime: 2020-12-19 16:36:12
 * @LastEditors: Please set LastEditors
 * @Description: In User Settings Edit
 * @FilePath: \server\test\prng.js
 */
// prng4.js - uses Arcfour as a PRNG

function Arcfour() {
    this.i = 0;
    this.j = 0;
    this.S = new Array();
  }
  
  // Initialize arcfour context from key, an array of ints, each from [0..255]
  function ARC4init(key) {
    var i, j, t;
    for(i = 0; i < 256; ++i)
      this.S[i] = i;
    j = 0;
    for(i = 0; i < 256; ++i) {
      j = (j + this.S[i] + key[i % key.length]) & 255;
      t = this.S[i];
      this.S[i] = this.S[j];
      this.S[j] = t;
    }
    this.i = 0;
    this.j = 0;
  }
  
  function ARC4next() {
    var t;
    this.i = (this.i + 1) & 255;
    this.j = (this.j + this.S[this.i]) & 255;
    t = this.S[this.i];
    this.S[this.i] = this.S[this.j];
    this.S[this.j] = t;
    return this.S[(t + this.S[this.i]) & 255];
  }
  
  Arcfour.prototype.init = ARC4init;
  Arcfour.prototype.next = ARC4next;
  
  // Plug in your RNG constructor here
  function prng_newstate() {
    return new Arcfour();
  }
  
  // Pool size must be a multiple of 4 and greater than 32.
  // An array of bytes the size of the pool will be passed to init()
  var rng_psize = 256;

module.exports = {
  prng_newstate
}
  